Engineering Help needed. Kubota RPR kit -No details.

countryguy

Member

Equipment
L2550/FEL/BH M6060/FEL ++
Nov 23, 2018
38
0
6
Fenton
This will be an interesting one for the serious orange engineer's here. (I hope).

a 90's BL4590 backhoe- Dipper/Boom repair kit came w/ zero instructions. I crafted a doc to ask Messicks for help, but thought I would post it here as well.

Here is the doc. w/ Pics and details on the RPR (repair) kit, the issue, and where I am stuck!

https://drive.google.com/file/d/1yLylbxwE6I29vEMEY7wiOTGGlAyzcLMW/view?usp=sharing

Either I have wrong kit... (but I did work w/ parts via phone on this one).
Or It's intended to do some field modification which some of you may know about!.
 

Dave_eng

Well-known member
Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
5,108
926
113
Williamstown Ontario Canada
Since no one has replied in 12 hours, I will throw out a couple of thoughts.

As I understand your written material, you are trying to fit the new parts inside the worn remnants which are part of the boom.

As a repair technique this seems wrong. Rather, the worn parts now welded to the boom should be removed and the new ones welded in.

Only do this if it makes sense to you!

Dave
 

GreensvilleJay

Well-known member

Equipment
BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
9,678
3,931
113
Greensville,Ontario,Canada
1) rings would be 'reinforcements' and welded to frame,bet you need to grind off existing welds though...
2) are the thin tubes 'spacers' ?
3) new pin doen't have end on it, like original, so TWO nuts and bolts hold it ?
4) new sleeve, would be welded onto frame. maybe grind out the old one first ??
5) does the pin slide nicely into the sleeve ?

one of those, it'd make sense being there ,holding onto the parts 'projects'.

I'm really now thinking you DO have to grind,cut,whack out the old 'sleeve', install/weld new one with the 'rings'.

Jay
 

rbargeron

Well-known member
Lifetime Member

Equipment
L5450, L48, L3250, L345 never enough attachments
Jul 6, 2015
1,136
211
63
western ma
Is there provision for lubing this pin/sleeve? Not clear from the pics - does the pin have drilled grease passages?
 

SidecarFlip

Banned

Equipment
M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
7,197
546
83
USA
If it was me, I'd take the boom or dipperstick apart and line bore the wallowed out bushings and weld in new ones. In fact, I'd do that for all the bushings that are slippy.

I'm going to do just that on a front end loader I have this summer, have some sloppy (worn out) female bushings myself. The disassembled weldments on the loader can be fixtured on my Bridgeport table and I'll 'line bore them with a boring head to the outside diameter of the bar stock I'll turn and bore to fit a new replacement through pin and I might make my own pins as well from bar stock. I'll weld in the replacement bushings, reassemble the weldments to the loader frame and call it good.

Kubota uses steel to steel pins and bushings on their equipment which is why it's very important to keep them greased I actually prefer a 660 CA bronze insert with a steel pin but to do that you need to retain the bronze bush as it cannot be welded. The alternative is to machine a bronze insert to ride in the steel bush and I would if it was a pivot of frequent motion. That is how a commercial unit is bushed and when the bush gets sloppy, you just replace it as it don't impact the fulcrum (pivot pin) at all.
 

countryguy

Member

Equipment
L2550/FEL/BH M6060/FEL ++
Nov 23, 2018
38
0
6
Fenton
Yes,
the new Pin which 2 bushings slide onto, which slide into new Tube has a grease passge and hole in center.
But- There is no zerk end on the new pin like the existing... (may reuse existing if long enough) Not sure if I can buy those to pound on and tack? I think someone posted here what that end w/ the zerk is called.

Is there provision for lubing this pin/sleeve? Not clear from the pics - does the pin have drilled grease passages?
 

countryguy

Member

Equipment
L2550/FEL/BH M6060/FEL ++
Nov 23, 2018
38
0
6
Fenton
Re: Sidecar reply- Engineering Help needed. Kubota RPR kit -No details.

Thanks SC-
  • At this point, the inside tube races (or tube supports) of the dipper are about 3/8" wide to 1/2" inside the boom. Plenty of support in there.
  • I am just going to put the new 1.75" tube onto the rotary table on the mill and take them down 5/8" depth by .02-3" OD to achieve a snug fit into the dipper Assy holes as is. (will clean up outside and such a bit first)
  • I'll weld the tube and new rings and it'll be a beefy assy then.
  • The new tube will be stationary. (welded onto the dipper frame). (squared and centered to each other)
  • The pivot will be via the bushings on the pin which rides inside the new tube (w/ grease holes). -PS- inside of the tube (Id) has a groove to prevent the bushings from sliding to gether). saw that today.
I think this is the intent of Kubota on this kit.

If it was me, I'd take the boom or dipperstick apart and line bore the wallowed out bushings and weld in new ones. In fact, I'd do that for all the bushings that are slippy.

I'm going to do just that on a front end loader I have this summer, have some sloppy (worn out) female bushings myself. The disassembled weldments on the loader can be fixtured on my Bridgeport table and I'll 'line bore them with a boring head to the outside diameter of the bar stock I'll turn and bore to fit a new replacement through pin and I might make my own pins as well from bar stock. I'll weld in the replacement bushings, reassemble the weldments to the loader frame and call it good.

Kubota uses steel to steel pins and bushings on their equipment which is why it's very important to keep them greased I actually prefer a 660 CA bronze insert with a steel pin but to do that you need to retain the bronze bush as it cannot be welded. The alternative is to machine a bronze insert to ride in the steel bush and I would if it was a pivot of frequent motion. That is how a commercial unit is bushed and when the bush gets sloppy, you just replace it as it don't impact the fulcrum (pivot pin) at all.
 
Last edited:

countryguy

Member

Equipment
L2550/FEL/BH M6060/FEL ++
Nov 23, 2018
38
0
6
Fenton
anyone know what you call the pin cap end w/ the ZERK ? I'll need to find one of those if I'm going to use the new one? on the new pin, It's not threaded in the open end... On the the original, w/ zerk-end/cap I'm not going to ruin trying to remove.. will reuse, but a good $30 pin if I can get the zerk/cap end someplace like mcmaster.
 
Last edited:

SidecarFlip

Banned

Equipment
M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
7,197
546
83
USA
Yeah... we had 10" last week.. still much of it on the ground! gonna be a fun winter in the Winter Wonderland state.
Reason I posted that is you can come down here and use my machine tools if you want. I have 4 lathes, a couple vertical mills and MIG, TIG, plasma and Smaw available and all the required tooling. Nice heated shop too.

I'll be gone next week, going hunting out west but I'll be back in a week to 10 days.

Winter wonderland my butt.. More like the dodgem state.....:eek: Nutty people and icy roads, heck of a combination.

I'd strip the fabrication, clamp it to the table (vertical mill) and bore them square and parallel. Far as the pin goes, counter bore it and it for a zerk, I think they are 1/4-28 You need to recess the zerk in the pin so it don't get wacked off.
 

countryguy

Member

Equipment
L2550/FEL/BH M6060/FEL ++
Nov 23, 2018
38
0
6
Fenton
Anyway, Thank you very much! Will kit in touch via PM. I'll send ya some info. We should chat.
-Update- PM sent.



Reason I posted that is you can come down here and use my machine tools if you want. I have 4 lathes, a couple vertical mills and MIG, TIG, plasma and Smaw available and all the required tooling. Nice heated shop too.

I'll be gone next week, going hunting out west but I'll be back in a week to 10 days.

Winter wonderland my butt.. More like the dodgem state.....:eek: Nutty people and icy roads, heck of a combination.

I'd strip the fabrication, clamp it to the table (vertical mill) and bore them square and parallel. Far as the pin goes, counter bore it and it for a zerk, I think they are 1/4-28 You need to recess the zerk in the pin so it don't get wacked off.
 
Last edited:

countryguy

Member

Equipment
L2550/FEL/BH M6060/FEL ++
Nov 23, 2018
38
0
6
Fenton
Update from Kubota- : Engineering Help needed. Kubota RPR kit -No details.

Update on the kit: Dealer Support- Kubota told my parts gal that this PN is listed as a Seal kit. Not a RPR/fabrication required repair kit. No other info. No instructions... and to Orange... it's a seal kit, Which it is clearly not. but- Someone knew the field failures requires a RPR kit, and I'll make it work.

Also, Told the BL was made by a co. called Arens (no clue on spelling) for Kubota. Not Woods as some suggested unless Woods bought this BL maker? So maybe both are right?

PArts: the VMC Mill is fired up, will do what I originally planned....turn down the 1.75 tube to fit the boom supports (post clean up and prep review).
The BUT... I'm still not sure if I weld that tube in or not into the dipper. That's my only concern from the plan above. I'll keep this going w/ some updated pics on how this all goes together and maybe as a group ya'll can advise on the do or do-not weld the tube bushing in.

Sight unseen, I know how this thread reads somewhat... unless you live it.. it's sort of a ramble. This is also for the next guy or gal that has a 4590 or 4690 w/ the same issue.. they'll know instantly what's up here too .

OK... calling Kubota support for myself just to waste another hour... w'ell see.
Peace and to all a good hunt if so inclined.
 
Last edited:

whitetiger

Moderator
Staff member

Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
2,542
1,059
113
Kansas City, KS
Re: Update from Kubota- : Engineering Help needed. Kubota RPR kit -No details.

Here are the instructions from the Kubota Knowlege search to install your repair kit. I put the part number in a part search, comes up as a dipper repair kit, not a seal kit. Someone got their numbers crossed.

70050-94394 Dipper Repair Kit
INSTALLATION INSTRUCTIONS
for BL4590 Backhoes
NOTE 1: See KUBOTA Service Bulletin SB94-16
for Service, Parts and Warranty Information
pertaining to this repair kit. If the dipper already has
a bushing type pin boss, follow Dipper Removal,
note #3 and steps 4 thru 7 under Kit Installation,
and Dipper Replacement instructions.
1. Park the tractor on a level floor where there is
access to a hoist with a minimum capacity of
2000 Ibs. Fully extend the boom and dipper so
they are horizontal and the bucket is resting
lightly on the floor. Lower both stabilizers to
ground contact.
2.
3.
4.
Place a jackstand under the boom, near the
boom and dipper joint. Bleed the hydraulic
system of residual pressure by moving all
backhoe control valve levers several times in all
directions. Disconnect both crowd (bucket)
cylinder hoses from their fittings on the boom.
Hang a lift sling or chain on the hoist and place
it around the dipper near the boom. Remove the
3/8***8221; locknut and 3/8-16 x 2-l/4 bolt from one
end of the dipper pivot pin, remove and discard
this pivot pin.
With the hoist, raise and swing the dipper up
and away from the boom. Lower the dipper onto
another jackstand to hold it off the ground.
KIT INSTALLATION
1. Using a disc grinder, remove all weld that is
holding the pin boss to the sides of the dipper.
Remove and discard the pin boss.
2. It may be necessary to slightly enlarge the holes
in the sides of the dipper to receive the new
larger diameter pin boss.
NOTE 2: DO NOT install the bushings in the new
bushing style pin boss until instructions are given.
3. Install, align with a square, and center the new
pin boss in the dipper. Tack weld it in place.
NOTE 3: If the dipper already has a bushing pin
boss, the new boss from this kit is not needed.
Remove both old bushings before proceeding.
Regardless of dipper application, make sure the
bushing bore in the pin boss is protected from weld
splatter before proceeding.
4. Place a reinforcing plate over
one end of the pin boss, flat
against the dipper. Weld the
OD to the dipper and the ID to
the dipper AND pin boss.
Repeat on the other side.
5. With a disc grinder, remove
excess weld to insure the
plates are flush with the
end of the pin boss.
6. Repaint the reworked area
with KUBOTA Orange paint,
spray can P/N 70000-73713.
Allow the paint to dry before
proceeding.
7. Inspect and make sure the bushing bore in the
pin boss is free of any weld splatter and paint.
Carefully install two new bushings.
DIPPER REPLACEMENT
NOTE 4: Dipper replacement is an exact reversal
of removal instructions 1 thru 4, with the exception
that a new unplated and heat-treated pivot pin from
this kit is reinstalled (Dipper Removal, step #3).
 

countryguy

Member

Equipment
L2550/FEL/BH M6060/FEL ++
Nov 23, 2018
38
0
6
Fenton
Re: Update from Kubota- : Engineering Help needed. Kubota RPR kit -No details.

WT-- I bet you are a GREAT Tech!

..and I called two Dealerships I'ved worked with, and my parts folks claimed to call Kubota DS... and got Nadda. Just like where I work anymore...Hard to find the right person w/ so much in the workplace. We all are doing 3 jobs anymore (( know I am)). This forum ROCKS and I'm on a LOT of them.
THANK YOU WT! Owe ya one on this.

This is pretty much how I was expecting it to go- I just did not know if I welded in the new Pin Boss (So it's not a tube eh' Da' Boss will be welded in)
Whoot! We're going to have a near-new 4590 for the 2x to 3x a year jobs. 4 new cyl rebuilts and a dipper & 9" that'll scoop ice-cream if I wanna :D )

Short recap on the key part: On the FAB side, the new pin boss that comes is 1.75" My 1.5" old Boss slopped all over in in the 1.72/73 dipper Boss tube mounts. So I'll turn that down to fit snug and square and weld her' up. Will post pics here for folks of the pre-fab, post-fab for the next poor soul. But it's a fun project! for $100... well worth the fix.






Here are the instructions from the Kubota Knowlege search to install your repair kit. I put the part number in a part search, comes up as a dipper repair kit, not a seal kit. Someone got their numbers crossed.

70050-94394 Dipper Repair Kit
INSTALLATION INSTRUCTIONS
for BL4590 Backhoes
NOTE 1: See KUBOTA Service Bulletin SB94-16
for Service, Parts and Warranty Information
pertaining to this repair kit. If the dipper already has
a bushing type pin boss, follow Dipper Removal,
note #3 and steps 4 thru 7 under Kit Installation,
and Dipper Replacement instructions.
1. Park the tractor on a level floor where there is
access to a hoist with a minimum capacity of
2000 Ibs. Fully extend the boom and dipper so
they are horizontal and the bucket is resting
lightly on the floor. Lower both stabilizers to
ground contact.
2.
3.
4.
Place a jackstand under the boom, near the
boom and dipper joint. Bleed the hydraulic
system of residual pressure by moving all
backhoe control valve levers several times in all
directions. Disconnect both crowd (bucket)
cylinder hoses from their fittings on the boom.
Hang a lift sling or chain on the hoist and place
it around the dipper near the boom. Remove the
3/8***8221; locknut and 3/8-16 x 2-l/4 bolt from one
end of the dipper pivot pin, remove and discard
this pivot pin.
With the hoist, raise and swing the dipper up
and away from the boom. Lower the dipper onto
another jackstand to hold it off the ground.
KIT INSTALLATION
1. Using a disc grinder, remove all weld that is
holding the pin boss to the sides of the dipper.
Remove and discard the pin boss.
2. It may be necessary to slightly enlarge the holes
in the sides of the dipper to receive the new
larger diameter pin boss.
NOTE 2: DO NOT install the bushings in the new
bushing style pin boss until instructions are given.
3. Install, align with a square, and center the new
pin boss in the dipper. Tack weld it in place.
NOTE 3: If the dipper already has a bushing pin
boss, the new boss from this kit is not needed.
Remove both old bushings before proceeding.
Regardless of dipper application, make sure the
bushing bore in the pin boss is protected from weld
splatter before proceeding.
4. Place a reinforcing plate over
one end of the pin boss, flat
against the dipper. Weld the
OD to the dipper and the ID to
the dipper AND pin boss.
Repeat on the other side.
5. With a disc grinder, remove
excess weld to insure the
plates are flush with the
end of the pin boss.
6. Repaint the reworked area
with KUBOTA Orange paint,
spray can P/N 70000-73713.
Allow the paint to dry before
proceeding.
7. Inspect and make sure the bushing bore in the
pin boss is free of any weld splatter and paint.
Carefully install two new bushings.
DIPPER REPLACEMENT
NOTE 4: Dipper replacement is an exact reversal
of removal instructions 1 thru 4, with the exception
that a new unplated and heat-treated pivot pin from
this kit is reinstalled (Dipper Removal, step #3).
 

whitetiger

Moderator
Staff member

Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
2,542
1,059
113
Kansas City, KS
Re: Update from Kubota- : Engineering Help needed. Kubota RPR kit -No details.

WT-- I bet you are a GREAT Tech!

..and I called two Dealerships I'ved worked with, and my parts folks claimed to call Kubota DS... and got Nadda. Just like where I work anymore...Hard to find the right person w/ so much in the workplace. We all are doing 3 jobs anymore (( know I am)). This forum ROCKS and I'm on a LOT of them.
THANK YOU WT! Owe ya one on this.

This is pretty much how I was expecting it to go- I just did not know if I welded in the new Pin Boss (So it's not a tube eh' Da' Boss will be welded in)
Whoot! We're going to have a near-new 4590 for the 2x to 3x a year jobs. 4 new cyl rebuilts and a dipper & 9" that'll scoop ice-cream if I wanna :D )

Short recap on the key part: On the FAB side, the new pin boss that comes is 1.75" My 1.5" old Boss slopped all over in in the 1.72/73 dipper Boss tube mounts. So I'll turn that down to fit snug and square and weld her' up. Will post pics here for folks of the pre-fab, post-fab for the next poor soul. But it's a fun project! for $100... well worth the fix.
I was just setting in my recliner and pushed a couple buttons... :D
 

D2Cat

Well-known member
Lifetime Member

Equipment
L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
12,901
4,269
113
40 miles south of Kansas City
Whitetiger, I appreciate all the help you have given me and others on this forum. It's guys like you that make it SO much different than other forums. Not someone spouting an opinion, just facts. Thanks.
 

whitetiger

Moderator
Staff member

Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
2,542
1,059
113
Kansas City, KS
Whitetiger, I appreciate all the help you have given me and others on this forum. It's guys like you that make it SO much different than other forums. Not someone spouting an opinion, just facts. Thanks.
Thanks, D2Cat..........

and I do have opinions..........:D:D, my wife says so!!!
 

countryguy

Member

Equipment
L2550/FEL/BH M6060/FEL ++
Nov 23, 2018
38
0
6
Fenton
Update pic- The Fix is in...Engineering Help needed. Kubota RPR kit -No details.

OK, the 4590 is all done. It took awhile to get this thing done.... Below are some pics of the dipper boom assy and weld up.
I also had to repair the boom swing Cyl which leaked. Then elected to just do the curl, dipper, and stablizer seals too. So, done, runs like new(ish), and... greased top to bottom. what a fun mess that is getting all the old dirt-cake grease-mortar out..(my own fault).


Pics of the dipper/boom repair fab-up. Welded in the new pin Boss to the dipper, then placed the larger support ring and welded inside and outside to dipper. Some grinding clean up to meet the 3.85" OD max space in the boom receiver. Pinned and greased... solid as a rock. No more beating anything latterly beyond a nudge!

pic 1: https://d
rive.google.com/open?id=1KNqUesP_AULDACb5StsGNnG2sA_YHjqP


Pic2: https://drive.google.com/open?id=1X8k5e9U2EG8XyeLCZ2tdgycgxj3rxwN3

Pic3: https://drive.google.com/open?id=1Q_9GVmL7MGkOOAw-zmGtjCmcQGAaU2OY
 
Last edited: